DE2221511B2 - Seat for gate valves without a housing - Google Patents

Description

The invention relates to a gate valve, the valve housing of which has a flow channel with a cylindrical Has inner surface and the wedge-shaped slide plate from at least one side

ίο an upper, a lower and two side sections existing continuously progressing surface formed by straight generators that with an annular sealing arrangement for contact with a correspondingly designed seat surface

is the valve body is provided and in all Points on the sealing line are determined by straight lines and tangents to the sealing line Have tangent planes that include angles with the spindle axis that have a minimum

ao angle of at least 20 °.

A gate valve of this type is known from DT-AS 12 45 664. The upper section of the seat this valve housing forms intersection lines with all the planes containing the spindle axis, the enclose the same angle with the spindle axis. To reduce the transverse dimensions of the housing this seat is pulled down on both sides of the flow channel to about half the height of the same. The lateral sections close tangentially at the same angle to the spindle axis to the upper section and lead as straight sections tangentially into the lower, section formed by the flow channel. Through the straight side sections will a possible reduction in the transverse dimensions of the housing has not yet been fully exploited. In DT-Gbm 19 54714 a gate valve is provided with a rubber-elastic sealing strip, V-shaped and rounded in the lower portion of the closure piece described in his Closing position seals radially in the lower section and axially in the upper section, the middle Line of contact in these sections in parallel to the spindle axis and to the axis of the flow channel perpendicular planes. In order for the slide plate to be pressed onto the housing seat area in the event of a leak Completion only a low spindle pressure is required, the sealing strips have the one described there Gate valve in the V-shaped area of the non-pressed closure piece compared to an enlargement the area of the slide plate pressed against the lower seat surface of the housing. Even Here, due to the V-shaped design of the side sections, the housing dimensions are not as small as possible realized.

From US-PS 24 20 849 it is already known in the lower region of the closure piece of a gate valve to unite two sealing rings into one and to reduce the housing dimensions of the Gate valve cut the sealing surfaces of the flow channel directly in a closed curve to leave, so that the sealing surfaces are almost concentric to the axis of the flow channel. the In this case, sealing surfaces are only at a small angle in the upper section with respect to the spindle axis inclined, so that there is relatively low sealing pressure and high friction at this point results.

In the DT-AS 12 85 Sl 8 a gate valve is described, its closing body with two soft sealing rings, which can be displaced transversely to the direction of flow is equipped, whose center lines in the upper and lower area of the closure body each run approximately in a plane, the lower of which is approximately perpendicular to the direction of flow, and the in its lower area on the sealing surface formed by the lower wall part of the flow channel sits and interacts in the upper area with sealing surfaces of the housing. At the dor. described Gate valves are the planes in which the center lines of the soft sealing rings run, in the upper area of the closing body at an angle to the direction of flow. This is to achieve that no point on the sealing surfaces in the housing runs parallel to the closing or opening movement. Here too are not yet the smallest possible housing dimensions with a given gasket inclination angle realized.

Furthermore, from DT-OS 19 22516 or DT-OS 19 57 560 gate valve known, the lower sealing surface sections on one of the cylindrical Inner surface of the flow channel are different level, the sealing surface sections are designed either as a recess or as a projection.

The object of the invention is to create a gate valve which, in addition to the advantages of approximately constant and as large as possible sealing surface inclination angle, particularly small housing dimensions should have.

The solution according to the invention consists in a Design gate valves of the type referred to in the preamble so that the individual sealing surface sections run almost concentrically to the axis of the cylindrical inner surface; that the crossing points of the sealing surface sections lie approximately in areas where planes of contact with the cylindrical Create the inner surface that enclose the minimum angle with the spindle axis; and that the middle lines of contact of the upper and lower sealing surface section parallel to the spindle axis and planes perpendicular to the axis of the cylindrical inner surface and the lateral sealing surface sections the upper sealing surface section with the lower sealing surface section approximately in shape connect a helical surface.

It is particularly advantageous if the minimum angle is 30 °.

The angle between the tangential planes and the spindle axis is expediently one more along almost constant than half of the sealing line encompassing sealing surface area.

In a further embodiment of the invention, the lower sealing surface section has an area which lies on a level deviating from the cylindrical inner surface and on the at each point its sealing line tangential planes can be placed, which essentially correspond to the spindle axis Include constant angle.

It is particularly advantageous if the area located on the other level is opposite to the cylindrical area Inner surface is designed as a recess or as a projection.

In a further embodiment of the invention, the angles between the tangential planes and the spindle axis are almost constant along the entire sealing line. This gives the advantage that the seal moves over the entire circumference of the sealing surface under the same conditions The compression of the seal, which is perpendicular to the normal to the sealing surface, is also at a predetermined lowering of the slide plate over the entire circumference of the seat surface constant. Change If you lower the slide plate, the compression also changes, but it decreases

ίο one again over the entire circumference of the seat uniform value. In this arrangement there is a further advantage that the slide plate ii its lower part is guided and supported at the end of the closing movement. This benefit is un the more important, the less the contact and guide surface of the slide plate in the grooves de: Valve housing down over the axis de: flow channel migrates out when the slide plate is in its closed position.

With the arrangement according to the invention it is enough that the gate valve is in the closed position is absolutely tight. Another advantage is that on the one hand there is a given angle can achieve minimal housing dimensions between the contact planes of the seat, on the other hand a maximum angle can be used for the gate valve body with a given space with minimal wear and tear.

The invention is described in the following description of exemplary embodiments in connection with mil the drawing explained in more detail. The drawing shows in FIG. 1 and 2 representations belonging to one another

to determine the intersection curve between the seat surface and the cylindrical inner surface of the flow channel, this inner surface in FIG. 1 in longitudinal section and in FIG. 2 is shown in cross section,

F i g. 3 shows a partial section through the valve housing in the longitudinal plane of symmetry,

F i g. 4 shows a partial section through the valve housing in the plane of symmetry directed to the longitudinal through 90 ° rotated transverse plane,

Fi g. 5 part of a floor plan,

6 shows two schematic representations for comparing the gate valve according to the invention with one known gate valve with wedge-shaped gate valve,

7 shows a longitudinal section through the valve housing of a second embodiment,

F i g. 8 is a cross-section along line 16-16 of FIG. 7;

F i g. 9 a floor plan,

Figures 10 to 12 correspond to Figures 7 to 9 Representations of a third embodiment, and in FIGS. 13 to 15 corresponding to FIGS. 7 to 9 Illustrations of a fourth embodiment.

Embodiments according to FIGS. 1 to 6

As can be seen from the drawings, the arrangement is symmetrical, both with respect to the longitudinal plane PP and with respect to the transverse plane QQ. Two seat surfaces? .6 are provided in an annular, continuously progressive design, which merge into one another.

In Figs. 3 to 5, the two plant or Seat surfaces 26 shown, which on the slide housing 1 symmetrically to the transverse symmetry

drive plane QQ are arranged and have a common closed contour. Each seat surface 26 delimited inside and outside in this way consists of four sections: an upper section I, a lower section II and two lateral sections III, which connect to sections I and II. The surfaces are designed so that in all points of the sealing line 31 the tangential planes of the contact surface form an angle of at least 20 ° with the direction of movement of the slide plate, preferably of the order of 30 °.

Starting from an angle of inclination of 30 ° of the tangential planes, the inner contour 29 or the sections I, II and III of one of the surfaces 26 or one of its halves, which lies on one side of the plane of symmetry PP , will be explained in more detail below. The other surface 26 is arranged symmetrically with respect to the transverse plane QQ. F i g. 1 shows the cylindrical inner surface 7 of the flow channel in longitudinal section, while FIG. 2 shows a cross section of this inner surface.

If one considers in Fi g. 2 the four contact planes TT of the cylindrical inner surface 7, which enclose an angle of 30 ° with the axis YY of the actuating spindle of the gate valve, it follows that the tangential planes along two upper generators J ¹ , J ' ² and along two lower generators K ¹ , K ^s tangent to the cylindrical inner surface 7.

Under this condition, a limiting curve U according to FIG. 1 can be drawn on the cylindrical inner surface 7, which curve consists of the following sections:

from a section AC, which consists of a rectilinear section running parallel to the axis YY corresponding to the direction of movement of the slide plate and corresponding to a planar section of the cylindrical inner surface 7 perpendicular to the axis of the cylindrical inner surface;

from a partial curve CDEFG, which runs in such a way that at all points, such as at point C, the tangent T of the curve encloses an angle of 30 ° with YY ;
and from a lower section GH, which is formed by a second rectilinear section parallel to the axis YY .

The curve U represents a limiting curve in the sense that between the generators J ¹ and K ¹ on the one hand and the generators J ' ² and K ² on the other hand, a surface can be constructed in such a way that their tangential planes along the intersection of this surface with the cylindrical inner surface 7 include a constant angle of 30 ° with the axis YY for the movement of the slide plate.

If one wanted to assume a steeper curve, the construction would be impossible. This limit curve U leads to a minimum opening of the valve housing between the two seat surfaces 26 in the event that a seat surface is sought which forms an angle of 30 ° or more with the axis YY along the curve 29, which is the intersection between the seat surface 26 and the cylindrical inner surface 7 represents. It should be noted that there is a limit curve for each predetermined value of the minimum angle.

Accordingly, this limit curve U

assume, however, one obtains a seat surface 26 which rotates or twists very quickly at certain points. It is therefore preferable to move a little away from this limit curve, specifically in the areas of the generatrices / ', K \ J ² , K ² , so that a seat surface 26 is obtained which warps less quickly. Under these conditions curve 29 corresponds to track abfg (see IF Fig. 1).

The F i g. 3 to 5 correspond to half of one of the seat surfaces 26 with its upper section I, lower section II and lateral section III. The points of interest that lie on the lower contour 29 of the seat surface are designated with a, b ... , £, h . The corresponding points on the sealing line are labeled α ¹ , b ¹ . .., while the corresponding points on the outer contour 30 with the letters a ² , b ² ... were designated.

The upper section I has the following characteristics:

the intersection of this section of the surface with the cylindrical inner surface 7 forms the arc abc of a rectilinear section of the cylindrical surface;

the section I is generated by straight lines which run parallel to that plane of symmetry PP of the gate valve which contains the axis XX of the flow direction and the axis YY of the direction of movement of the slide plate;

every straight line b, b ² on the seat surface that passes through a running point b between points α and c lies in a plane that passes point b and at this point contains the tangent to the inner contour 29 and an angle due to the design of 30 ° with the axis YY for the movement of the slide plate; drr route section, such as b, fe ¹ , has a length i of almost constant value; b ^l is the corresponding point on the sealing line 31 of each of these straight lines.

This condition determines the sealing line 31 on the seat surface 26. The section b, b ² has the length 2 /. It corresponds to the width of the specified seating area. Point b ² determines the theoretical outer boundary of the seat area. In fact, the seat can practically extend beyond point b ² until it meets the wall of the slide valve housing again.

Since the section b, b ^{2 is} small in relation to other dimensions of the seat surface, and since the seat surface gradually twists, the tangential plane at the current point b ^{l of} the sealing line 31 drawn through the upper part of the seat surface forms an angle of approximately with the vertical 30 °.

The lower section II of the seat surface forms a cylindrical surface which is concentric to the axis XX and runs exactly in the continuation of the cylindrical inner surface 7 of the flow channel.

In this section the seat surface 26 loses its individuality and coincides with the generators of the lower one Section of the cylindrical inner surface 7 to-

together. The sealing line follows the straight section g \ h ^x . The angle between the vertical and the plane of contact, which is placed along the sealing line on the seat surface, increases in the area between g ^l and / i ¹ from 45 ° to approximately 90 °.

Each lateral section III connects the upper section I in a continuously progressive manner with the lower section II and in the embodiment according to FIGS. 3 to 5 consists of three zones:

a) Zone cd, d ² , c ² . This is a part of a plane which is inclined by an angle of 30 ° with respect to the axis XX of the flow direction and encloses an angle of 30 ° with the axis YY according to FIG.

b) Zone dff ² d ² . It is a ruled surface which can be developed from the horizontal generatrices which lie against the curve dj drawn on the cylindrical inner surface 7. In every running point, for example at point e between points d and /, the generating line forms the horizontal straight line, which lies in a plane containing the tangent at point e of the curve de and encloses an angle of 30 ° with the vertical. The plane of contact of the seat surface at the current point e on the curve de thus forms an angle of 30 ° with the axis YY in this construction. Since the route section ee ^{l is} small in relation to other dimensions of the seat surface and since the seat surface is gradually twisting, the angle between the contact plane at the current point e ¹ on the sealing line 31 drawn on the seat surface and the vertical is close to 30 °. A precise transition from the level cdd ² c- to the upper section I of the seat surface and to the area df] "- d ^{l of} the lateral section III takes place only at points c and d. In these points, the contact planes ^{correspond to area cdd 2} c ² , namely the contact plane at point c for the upper section acc * a ² and the contact plane at point d for section ^{dff 2} d ^2. In points c ² and d ^2, however, the contact planes of the surfaces to be connected differ slightly from the assumed plane cdd ² c * . It is therefore necessary to slightly level out the connection point along the generators cc ² and dd ² on the casting model.

c) Zone jgg ^l f ² . It is a ruled surface with almost the same definition as for the surface ^{dff 2} d ² . It can be developed from the horizontal generatrices which lie against the curve jg drawn on the cylindrical inner surface 7 of the flow channel. However, the angle between the vertical and the plane of contact of the seat surface increases at every point between points / and g from 30 ° to 45 ° if this point under consideration moves from / to g. This zone corresponds to the junction between the two seat surfaces 26. The union of these two seat surfaces takes place along the line 35 or / ² g ', which due to the above-mentioned symmetry in FIG. 3 coincides with the vertical axis of symmetry of this figure.

In the present exemplary embodiment, the assumed geometric construction is such that, apart from the general relationships described above, the connecting line of the two seat surfaces 26 represents a straight line / ² g ¹ , namely the

ίο tangent at point / ² on the straight-line section through the cylindrical inner surface 7 (see. Fi g. 4).

In the embodiment described above, the result is that the angle between the vertical and the tangential plane of the seat surface along the section a ^l to / 'on the sealing line is practically constant and is approximately 30 °. The same applies to the counterpart of the sealing surface, which is arranged symmetrically to the plane PP . Along the section between f ^l and h ^x on the sealing line and along the counterpart lying symmetrically to the plane PP , the angle between the vertical and the tangential plane of the seat surface increases progressively from 30 ° to 90 °.

On the basis of FIG. 6 shows how the size of the opening of the valve body, seen in the flow direction, is reduced from the length L to the length / by the seat surface construction according to the invention, if L means the size of the opening of a gate valve (with the same sealing surface inclination angle, in the known manner a conventional slide plate with two flat sealing surfaces is used which are inclined by 30 ° with respect to the axis YY . This means that the value I is on the order of half of the value L. The invention thus offers the possibility of practically halving the space requirement to reduce.

Embodiment according to FIG. 7 to 9

That section of the seat surface 26 a which lies above the diametrical plane of the cylindrical inner surface 7 of the flow channel is modified as follows:

The seat surface 26 α is generated at each point m between the points α and η by a straight line om which is supported on the axis XX of the cylindrical inner surface 7 and lies in that plane which the tangent at point m to the curve 29 a of Intersection between the cylindrical inner surface 7 and the seat surface 26 contains α and includes an angle of 30 ° with the axis YY of the direction of movement of the slide plate.

This solution ensures a homogeneous production of that part of the seat surface 26 α which lies above the horizontal plane XX running perpendicular to the plane PP. At the same time, the reworking that has to be carried out on the cast model according to the first embodiment at the level of the generatrix cc ² dd ^{2 is} avoided.

Embodiment according to FIGS. 10 to 12

The valve housing according to FIGS. 10 to 12 has, compared to the description above, a Number of differences, namely:

the distance between the two seat surfaces 46 α is chosen such that these seat surfaces do not connect to one another in their lower sections;

509581/225

the sections eg and # / i of the inner contours 50 α lie just like the sections ac and ce on the cylindrical inner surfaces of the flow channel arms 41 and 42. The sections gh and ac represent straight sections of the cylindrical inner surfaces of the flow channel arms 41 and 42 are the associated sections of the outer contours 51 a on the bottom 47 "of the middle section 44" and on the side walls of the transverse housing attachment cs 43, which is directly connected to the middle section;
the straight sections of the generatrix for the seat surfaces corresponding to the sections eg and gh of the contours 50 α can be developed in the same way as the areas corresponding to the sections ac and ce. This means that the straight line section is created at each point by an intersection of the radial planes with one of the two contact planes placed on the contour and inclined by 30 ° with respect to the axis YY. The middle section has the shape of a recess of trapezoidal shape, specifically seen in the radial middle section. In the vertical section corresponding to the plane PP , the flanks are inclined by 30 ° with respect to the axis YY.

Embodiment according to FIGS. 13 to 15

The valve housing according to FIGS. 13 to 15 differs from the embodiment described above only in that the bottom b of the central portion 44 b has a smaller radius of curvature than the Durchflußkanalarnie 41 and 42 and accordingly has the shape of a Vorspnings, which, seen in radial center section, is designed as a trapezoid. A vertical section corresponding to the plane PP shows that the flanks are inclined by 30 'with respect to the axis YY . The plane of contact at each point of the contour, which includes an angle of 30 ° with the YY axis and serves to determine the straight line section of the seat surface 46 b at this point, does not correspond to the plane of contact that is used for

ίο Generation of the seat on the slide valve housing according to FIGS. 10 to 12 is used. In the present case, the seat surfaces in their lower section must turn their curvature against the flow channel arms 41 and 42, and not, as in the previous embodiment, against the middle section 44 a. The seat surfaces of the slide plates used with the slide valve housings and the elastic sealing arrangements carried by these seat surfaces have exactly the same shape as the surfaces 46, 46 α and 46 b of the slide valve housings. In the two other embodiments according to FIGS. 10 to 12 and FIGS. 13 to 15, the central hollow section 44 α or the central raised section 44 b is relatively narrow. Two separate seal assemblies with no common portion are therefore used, which are separated from one another by the body of the slide plate. Thus, the slider body is located between the two sealing arrangements self directly cut on the central exhaust α 44 or 44 b on.

In the embodiments according to FIGS. 10 to 12 and FIGS. 13 to 15 correspond to the angle between the vertical and the tangential plane of the seat along the sealing line at least approximately a constant angle of over 20 °, preferably of 30 °, over the entire Circumference of the sealing surface.

In addition 5 sheets of drawings

Claims (7)

Patent claims: 1. Gate valve, the valve body of which has a flow channel with a cylindrical inner surface and whose wedge-shaped valve plate carries, at least on one side, a continuously progressing surface consisting of an upper, a lower and two side sections, formed by straight generatrices, which abuts with an annular sealing arrangement a correspondingly designed seat of the valve body is provided and in all points on the sealing line by straight generators and tangents to the sealing line has certain tangential planes which include angles with the spindle axis that do not fall below a minimum angle of at least 20 °, characterized in that the individual Sealing surface sections (I, II, III) run almost concentrically to the axis (XX) of the cylindrical inner surface (7); that the transition points of the sealing surface sections are approximately in areas (J ¹ ; / - '; K ¹ ; K ² ) where contact planes (T) can be applied to the cylindrical inner surface before which enclose the minimum angle with the spindle axis (YY); that the middle line of contact of the upper and lower Dictitflächenabiichnittes (I, II) runs in planes parallel to the spindle axis (YY) and perpendicular to the axis (XX) of the cylindrical inner surface and the lateral sealing surface sections (III) the upper sealing surface section (I) with the lower sealing surface section (II) connect roughly in the form of a helical surface. 2. Gate valve according to claim 1, characterized in that the minimum angle is 30 °. 3. Gate valve according to claim 2, characterized in that the angle between tangential planes and spindle axis (YY) is approximately constant along a sealing surface area (26 a, 46, 46 a, 46 b) encompassing more than half of the sealing line (31). 4. Gate valve according to claim 1 to 3, characterized in that the lower sealing surface section (II) has a region (44 a; 44 b) which is on a level deviating from the cylindrical inner surface (7) and on which at each point its sealing line tangential planes can be placed which enclose a substantially constant angle with the spindle axis (YY). 5. Gate valve according to claim 4, characterized in that de »on the other level area (44 a) opposite the cylindrical inner surface (7) is formed as a recess is. 6. Gate valve according to claim 4, characterized in that the region (44 b) lying on the other level is designed as a projection with respect to the cylindrical inner surface (7). 7. Gate valve according to one of claims 4 to 6, characterized in that the angles between the tangential planes and the spindle axis (Y-Y) are approximately constant along the entire sealing line.